1. Field
Embodiments relate to a semiconductor device.
2. Description of the Related Art
An integrated circuit device using semiconductor devices may be fabricated by integrating various individual circuit devices, e.g., an electric field effect transistor such as a metal-oxide semiconductor field effect transistor (MOSFET) or a complementary MOSFET, a resistor, a capacitor, etc., into one chip. Generally, such individual devices have been continuously scaled down to provide enhanced performance in relation to operating speed and/or power consumption. For example, in dynamic random access memory (DRAM), demands for improving the operating speed and power consumption have resulted in increased integration of DRAM.
However, if a clock frequency of a semiconductor device is increased for faster operating speed, noise may also increase. In DRAM, when the operating speed is increased, noise—which may momentarily occur between operating voltages, e.g., power voltage Vdd and ground voltage Vss during a reading and/or writing operation—may increase; and thus the operating speed may decrease. Also, a sensing margin of a sense amplification unit within a semiconductor device may be narrowed.
To improve the operating speed and reduce noise, a method of forming a decoupling capacitor which functions as a noise filter has been proposed. In a semiconductor device such as DRAM, the decoupling capacitor may be formed in a peripheral circuit region and may have a structure similar to that of a capacitor formed in a memory cell array region. The decoupling capacitor may have a plurality of bottom electrodes that may be formed in a line on contact plugs having, e.g., line shapes or bar shapes. Two or more decoupling capacitors may share one contact plug so that a large capacitance may be obtained. Dielectric material layers may be formed on each of the bottom electrodes of the decoupling capacitors. Top electrodes may be formed on the dielectric material layers.
The bottom electrodes of the decoupling capacitors may be formed using mold layers formed on the contact plugs. In this case, the bottom electrodes may be formed on inner sidewalls of contact holes, which may be formed in the mold layers, and on portions of the contact plugs exposed in the contact holes.